1. Field of the Invention
The invention concerns a procedure for the production of tablets and capsules of natural substances of vegetable origin, without the use of technologic excipients or adjuvants, in the field of herbal medicine and pharmaceutical products.
2. Description of Related Art
At present it is possible to produce tablets, containing natural substances of vegetable origin, through the compression of a mixture of dry extracts and/or herbal powders with the addition of a number of excipients, also called technologic adjuvants. The latter are normally synthetic or semi-synthetic substances and, according to their functions, they are divided into:
binders: their function is to tie the powder particles together to obtain the tablet; PA1 lubricants: their function is to reduce the adhesion of the powders to the machines and, in particular, to the matrix and punch with which the tablets are produced, as well as to increase the flowability of the mixture of powders during the compression phase.
Therefore, the tablets and capsules obtained through the known technologies normally contain 30%-60% of their weight in excipients that must be used only and exclusively for technological reasons. Therefore it is impossible to produce, at the state of the art, 100% natural tablets which contain only dry extracts and/or herbal powders.
On the other hand it could be theoretically possible to eliminate the need of technologic adjuvants by prior granulation of the mixture to be pressed. The hypothetically produced granulate could in fact lose its characteristics of low flowability and binding power or excessive adhesiveness and it could be correctly pressed.
But, even with the state of the art machines and methods for granulation (wet, dry, fluid bed), it is not possible to granulate without the use of excipients and more specifically of binding agents.
This invention rises from the observation that dry extracts and herbal powders, but in particular their mixtures, usually possess good binding properties, but have very little flowability. It would therefore be possible to produce tablets and/or capsules simply by modifying this last characteristic, that is by increasing the flowability of the mixture. Using the granulation process, the flowability of mixture is considerably improved, but to obtain granules this process requires the use of binding agents or the use of liquids (water or solvents) which, after having caused the aggregation of particles into granules, must be evaporated and therefore taken away from the granule.
The latter solution would be the only one possible to obtain a granulate and therefore a tablet or a capsule without excipients, but in this specific case, since the dry extracts are extremely hygroscopic, due to their low humidity content (&lt;5%), it is technically impossible to have a wet granulation of the product.